Printable View
Have 115 hp Johnson serial #G04484085
Model #J115TSLECM Compression numbers are 120, 115,110 and 95. The serial number on the powerhead is G3602667. Can someone run these numbers to see what is going on with this and can you tell if this is the original powerhead that came on this engine.? Is the cyclinder with the 95 too low and in need of rebuilding. Wouldn't this cause loss of power and speed?
Modified by Dr. No at 6:52 AM 11/10/2009
Ever been decarbed? Try that then get new comp #'s
If the tag on the bracket says G04484085 then the original head will have that on the welsh plug G3602667. Looks like a replacement head. I'll see if I can find anything on it.
now this maybe a long shot and completely off target, but, it does seem strange that the numbers are always decreasing, are you sure you did the tests OK and the gauge is OK? if so, as mentioned, decarb, fingers crossed, if still the same run it untill it is really "sick" then decide what to do, it may go for years (or it might fail tomorrow)
Ok but don't know anything about this powerhead. Hopefully Championman finds some info on these numbers. Thanks to you and Championman for your help
Yeah it is a new guage and used it on a 225 Mariner first time with all cyclinders reading good. Did this one several times just to make sure and got the same reading each time so I think that the guage is good. 95 is pretty low isn't it?
yeah, it is a bit low, but I have seen a lot worse, and some of those motors are still working just fine, is there some issue with your motor, or did you do the compression tests "because"? and don't forget to do a decarb, might just get compression back up again (maybe)
are both of your low numbers on the same side?....... could be a bad gasket.
ane as said above a decarb MAY help you out..... cross your fingers for a gasket or a simple decarb http://www.bassboatcentral.com/smileys/praying.gif
i bet it shakes at idle pretty bad too.
how do the spark plugs look?..... any of them extra clean?
Yes both low numbers are on the same side. All spark plugs look good and look the same
Dr. No is a friend of mine and trying to help me out on my motor problem. This motor blew up about 6 months ago and I had it rebuilt but it hasn't ran right since. RPM gauge doesn't work so I can't tell what RPM's its up to. Now, the boat ran about 52 to 54 MPH, not gps but gauge MPH before rebuild and now tops out at 48. The 1st time I got it back after break in it topped out at 42 MPH and he went back and did something else, what I don't know, powerhead?. It also has lost power coming out of hole. Seems to me the mechanic may have cut some corners but I'm not sure exactly what all he has done. He told me he put another powerhead on it this time and obviously that is the case. Dr. No and I did this compression test out of curiosity and we're trying to find out what he has done in changing powerhead or whatever else is the case. Also the mechanic mentioned trying another prop or raising motor but nothing has changed from the time it blew up and as I said it ran 52 to 54 then. I'm looking for enough knowledge to be able to question mechanic on this. Thanks for anymore help on this matter
im sorry i just re-read the entire thread and jjust realized it had been freshly rebuilt.
was it a complete re-build?
sometimes ,more often than not unfortunately, the bad cyl are all that are re-built to save money................. costs are outrageous if you do an entire re-build
Well, to be honest with you, I'm not exactly sure what all has been done. I've known the mechanic for years and I'm really just trying to trust what he's telling me. First he told me he sent the original head to Florida and had it bored. That's the time it wouldn't run but 42 MPH. I took it back and he said he got another head and installed it. It was better, but still didn't have the power it had. My brother is original owner and he was out with me about a month ago and he was saying it had lost a lot of power. I then took it back a third time and he said he put another head on it and that is now the one Dr.No and I just did the compression test on. I'm about an hour into this break in which is the third one. He only charged me $750 to rebuild it and from what I've been told that wouldn't cover a motor rebuild. When I picked it up this time he said something about raising the motor up so i felt like it was going to be the same thing all over again because he knows its still not going to have the power it should. Would those compression numbers cause it to lose this power and speed?
your comp #s should be within 10% of each other to run properly....... any more than 10% and yes it will drop power which will cost you speed.
rebuilding 1 or 2 bad cyls is a very common practice when it comes to outboard engs. i will not do it, but it does happen... maybe thats how it got rebuilt so cheaply, or maybe could it be he replaced the cyl head and not the eng/head unit?..... the cyl head is close to $300, depending on hourly rate and adding the gasket and what nots it could be this is what he is fixing.
its hard to speculate on what work he did for $750 but i can tell you that you are very right when when you said that wouldnt cover a rebuild......... that would get you started but not even close to finishing.... a couple thousand, at least, would be closer.
you can go here http://shop2.evinrude.com/ext/...6ec1c and price some parts and you will see what i mean:: pistons over $120 each---- bearings over $60 each-----gasket set over $150-----etc...
i have seen a few head gaskets give out and it can cause symptoms like you described: uneven comp, slow hole shot, low top end, erratic idle, poor fuel economy, etc..
if it was a rebuild was the eng properly broken in?......... the break-in period is crucial for performance and longevity........
did your friend not get an itemized bill?........ anything i work on i will hand the customer the parts receipts with my receipt, i dont add anything to the parts (yes i have seen shops get a 20% discount on parts then charge the customer full price)
Championman did you ever find out any info on these numbers?
Johnson 115 hp Serial G04484085
Model J115TSLECM
Welsh plug on powerhead #G3602667
Thanks
No info available via dealer info.
yes the break in has been properly done all three times. if its not running right after this one, which i have a good feeling its not, dr.no and i are going to try the gasket replacement and just go from there. maybe we will get lucky. thanks for the info
Thanks for looking
you need to check the head.
when you get the head off get you a piece of glass and some really fine sandpaper (1000 grit or so)
then take the sandpaper put it on the glass and rub the head in a figure 8 motion..... do not apply uneven pressure nor work it like a file..... no straight motions only circular.
what you are trying to accomplish is to find out if the head is warped..... all gasket surfaces should get shiny at the same time..... if it is warped it may be fixable by doing the exact same thing you did to check to see if ti is warped.....
the glass is to make sure your surface is true..... i wouldnt trust a kitchen nor a shop table... at least not either of mine.
we will check the head by doing that before replacing gasket. thanks again for the pointers and advise
Pull the head off, take it to NAPA and have them put it on their belt sander. If the guy knows what he is doing you will have a flush head and will need a new gasket. Use some sealer and torque it down and run it for 5-10 hours and retorque it after running it and letting it cool down a few hours. http://www.bassboatcentral.com/smileys/thumbsup2.gif